package com.wanxi.servlet;

import com.alibaba.fastjson2.JSONObject;
import com.wanxi.dto.ImgDTO;
import com.wanxi.dto.ResultDTO;
import org.apache.commons.fileupload.FileItem;
import org.apache.commons.fileupload.disk.DiskFileItemFactory;
import org.apache.commons.fileupload.servlet.ServletFileUpload;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.*;
import java.util.List;
import java.util.UUID;

@WebServlet("/upload")
public class FileServlet extends HttpServlet {
    private static final String UPLOAD_DIRECTORY = "/upload";

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        // 检测是否为多媒体上传
        if (!ServletFileUpload.isMultipartContent(req)) {
            // 如果不是则停止
            PrintWriter writer = resp.getWriter();
            writer.println("Error: 表单必须包含 enctype=multipart/form-data");
            writer.flush();
            return;
        }

        // 配置上传参数
        DiskFileItemFactory factory = new DiskFileItemFactory();
        // 设置内存临界值 - 超过后将产生临时文件并存储于临时目录中
//        factory.setSizeThreshold(MEMORY_THRESHOLD);
        // 设置临时存储目录
//        factory.setRepository(new File(System.getProperty("java.io.tmpdir")));

//        解析前端传递过来的数据
        ServletFileUpload upload = new ServletFileUpload(factory);

        // 设置最大文件上传值
//        upload.setFileSizeMax(MAX_FILE_SIZE);

        // 设置最大请求值 (包含文件和表单数据)
//        upload.setSizeMax(MAX_REQUEST_SIZE);

        // 中文处理
        upload.setHeaderEncoding("UTF-8");

        // 构造临时路径来存储上传的文件
        // 这个路径相对当前应用的目录
        String uploadPath = req.getServletContext().getRealPath("./") + File.separator + UPLOAD_DIRECTORY;


        // 如果目录不存在则创建
        File uploadDir = new File(uploadPath);
        if (!uploadDir.exists()) {
            uploadDir.mkdirs();
        }

        try {
            // 解析请求的内容提取文件数据
//            Integer.parseInt("");
            @SuppressWarnings("unchecked")
            List<FileItem> formItems = upload.parseRequest(req);

            if (formItems != null && formItems.size() > 0) {
                // 迭代表单数据
                for (FileItem item : formItems) {
                    // 处理不在表单中的字段
                    if (!item.isFormField()) {
//                        拿到文件名
                        String fileName = new File(item.getName()).getName();
//                        String filePath = uploadPath + File.separator + fileName;
//                        文件名可以一样？
//                        需要修改文件名，可以对名称设计一个随机数，也可以设计唯一值，也可以用毫秒数
//                        a.jpg;
//                        UUID.randomUUID()+"---a.jpg"
//System.currentTimeMillis()+"----a.jpg";
                        fileName = System.currentTimeMillis() + "----" + fileName;
                        String filePath = uploadPath + "/" + fileName;

                        File storeFile = new File(filePath);
                        // 在控制台输出文件的上传路径
                        System.out.println(filePath);
                        // 保存文件到硬盘
                        item.write(storeFile);

//uploadPath:D:\wanxi\step-4\canyin04-20230213\out\artifacts\canyin04_2023
                        copyFile(storeFile, getWebFile(uploadPath, fileName));
//                        item.write(getWebFile(uploadPath, fileName));
                        String path = UPLOAD_DIRECTORY + "/" + fileName;
                        resp.getWriter().println(JSONObject.toJSONString(ResultDTO.builder().code(0).data(new ImgDTO(path, path)).build()));
                    } else {
                        System.out.println(item.getName());
                    }
                }
            }
        } catch (Exception ex) {
            ex.printStackTrace();
        }

    }

    private void copyFile(File storeFile, File webFile) {
        try {
            InputStream inputStream = new FileInputStream(storeFile);
            int read = 0;
            OutputStream outputStream = new FileOutputStream(webFile);
            while ((read = inputStream.read()) != -1) {
                outputStream.write(read);
            }
            outputStream.close();
            inputStream.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    /**
     * 创建一个web下面的地址
     *
     * @param uploadPath
     * @param fileName
     * @return
     */
    private File getWebFile(String uploadPath, String fileName) {
        String webPath = uploadPath.split("out")[0] + "/web/" + UPLOAD_DIRECTORY;
        File webFile = new File(webPath);
        webFile.mkdirs();
        File newPath = new File(webFile, fileName);
        return newPath;
    }
}
